Tanner crab (Chionoecetes bairdi)
Source-cited species reference: taxonomy from WoRMS, biology from SeaLifeBase, occurrence map from GBIF, description from Wikipedia.
Last updated
via Wikipedia: Chionoecetes bairdi · Public domain
Chionoecetes bairdi is a species of snow crab, alternatively known as bairdi crab and tanner crab. C. bairdi is closely related to Chionoecetes opilio, and it can be difficult to distinguish C. opilio from C. bairdi.
Both species are found in the Bering Sea and are sold commercially under the name "snow crab." Tanner crabs have suffered from overfishing and as a result strict controls have been placed on tanner crab fisheries. It was named by Mary Jane Rathbun, a Smithsonian employee who became one of the leading authorities on crab taxonomy. She named the crab for Spencer Baird, her mentor, who in the 1880s as Secretary of the Smithsonian Institution and head of the United States Fish Commission, had given her her first position.
Scientific classification
- KingdomAnimalia
- PhylumArthropoda
- CladePancrustacea
- ClassMalacostraca
- OrderDecapoda
- SuborderPleocyemata
- InfraorderBrachyura
- FamilyOregoniidae
- GenusChionoecetes
- SpeciesChionoecetes bairdi
Named by M. J. Rathbun, 1924
Close relatives
Other species of Chionoecetes with a Codexery entry.
- Snow crab Chionoecetes opilio
Sources: Wikipedia taxobox: Chionoecetes bairdi (CC BY-SA 4.0) · order, family and genus agree with WoRMS AphiaID 368558 (CC BY 4.0)
How big is it?
Largest length in the source, 0.15 m, next to a 1.8 m person.
Diagram: drawn by Codexery, schematic shapes to scale (not a likeness). Length: SeaLifeBase species summary
Where the tanner crab (chionoecetes bairdi) has been recorded
Each dot is a place where the species has been observed and reported (12,681 records, half-degree grid) — not a modelled range. 20 inland records left out (institution coordinates). 4 isolated far-off records not drawn.
Map: drawn by Codexery. Data: GBIF occurrence search (records CC0 / CC BY) · Natural Earth basemap (public domain)
Classification (WoRMS)
Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Arthropoda · Class: Malacostraca · Order: Decapoda · Family: Oregoniidae · Genus: Chionoecetes.
Accepted name: Chionoecetes bairdi · Authority: Rathbun, 1924 · Taxonomic status: accepted · AphiaID: 368558.
Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=368558 (CC BY 4.0). Accessed 2026-09-25.
Biology and life history (SeaLifeBase)
Measured values published by SeaLifeBase for Chionoecetes bairdi. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.
Maximum length: 15 cm · Depth range: 9–466 m · Habitat zone: benthic · Vulnerability index: 32 of 100 · Fishery importance: commercial.
SeaLifeBase notes: Maximum depth from Ref. 104115. Found in continental shelf. Epibenthic (Ref. 8740). Typically inhabits muddy substrates but also on sandy bottoms or on gravel in shallow waters.
It feeds on clams, other crabs, barnacles, shrimps, polychaetes, ophiuroids, and fish. It is preyed on by demersal fish, skates, larger crabs, octopus, and sea otter. Migration: Offshore migration with age, primiparous females mate in shallow waters while multiparous females mate in deeper waters. Males move upward into the littoral zone during spring molt.
Diseases: (1) Bitter crab disease, caused by a dinoflagellate of the genus Hematodinium ; the dinoflagellate replaces the crab's blood cells, causing the shell to turn pinkish-ivory in color and imparts a bitter taste to the crabmeat. (2) Black mat syndrome, a fungal infection; black tar-like covering the crab's shell, also prevents molting and may cause death (Ref. 101937).
Source: SeaLifeBase species summary (SpecCode 26935) — https://www.sealifebase.se/summary/Chionoecetes-bairdi.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.
Distribution and occurrence records (GBIF)
12,681 georeferenced occurrence records for Chionoecetes bairdi are published through GBIF from 3 countries or marine areas. The map above plots 283 distinct locations from a sample of 3,000 records, omitting 20 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.
Most records by country or area: United States of America (12,153); Canada (523); Russian Federation (5).
The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.
Source: GBIF Occurrence Search (taxonKey 2226642) — https://www.gbif.org/occurrence/search?taxon_key=2226642&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=368558 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.
Description and natural history (Wikipedia)
Tanner crabs are considered a short-tailed or "true" crab. They are decapods with pincer claws on their frontmost pair of legs. They can live over a decade with most adults reaching 1 to 4 lbs by the time they reach adulthood, usually after about five years.
Females will incubate fertilized eggs for a full year before hatching during spring plankton blooming season. The larvae are at first able to swim, but lose this ability and settle to the bottom after about two months. The tanners' diet consist mostly of other ocean bottom crustaceans, clams and worms.
Bottomfish and humans are their main predators. Little is known about their social structure except that the sexes remain mostly separate except during mating season. Tanner crabs are vulnerable to bitter crab disease.
Fisheries
Due to the massive harvests, numbers declined sharply, with only 1200000 lbs harvested in 1984. Sensing the danger of overfishing tanner crab to the point of extinction, legislators and fisheries managers closed tanner crab fishing entirely in 1986 and 1987. Policy adjustments were made to limit the catch, but the fishery was closed again in 1997 due to a very poor harvest in 1996.
In the mid-2000s fisheries managers introduced a "Crab Rationalization Program" based on similar programs in the North Atlantic and New Zealand. The program introduced individual fishing quotas based on each crab fishing boat's previous catches and a requirement that a percentage of the catch be offered for sale in the regions where it was caught.
This program was popular with environmental and conservation groups, although some small-scale crab fisherman complained that it placed them at a disadvantage as they could never catch more than their allotted share even if there were more crab available. In addition to overfishing, researchers from the School of Fisheries and Ocean Sciences have hypothesized that prevailing winds may affect crab population numbers from one year to the next.
Source: Wikipedia: Chionoecetes bairdi — https://en.wikipedia.org/wiki/Chionoecetes_bairdi (CC BY-SA 4.0). Accessed 2026-09-25.
Related in Tanner crab
Links follow this subject's own source article.
Elsewhere in Tanner crab
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Chionoecetes bairdi (CC BY-SA 4.0).
- Classification: the source article's taxobox; order, family and genus checked against WoRMS, the World Register of Marine Species (CC BY 4.0).
- Occurrence records: GBIF (CC0 / CC BY). Basemap: Natural Earth (public domain).
- Biology values: SeaLifeBase species summary (CC BY-NC 3.0, non-commercial).
- Word definitions: the , each quoted from its Wikipedia article.
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